Denis Defreyne

[dəˈni] • pronouns: he/him
+49 1573 1969 173

I am a software engineer with extensive experience in backend and frontend development, and comfortable with infrastructure, security, and reliability. I’m good at technical writing, and have a sense of visual design and UX.

I am committed to creating an inclusive culture that’s built on communication and collaboration, and where people can learn and grow.

I use technology only as a means to an end, and what I build will put the user’s needs first, taking into account usability and accessibility.


July 2021 – present

Software Engineer, Shopify

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February 2021 – June 2021

Software Engineer, developer tools, Pitch

Improve tooling to speed up build pipelines and increase resiliency.

July 2020 – present

Software Engineer, closecontact

Built a privacy-first contact-sharing solution for Berlin clubs

July 2019 – December 2020

Software Engineer, BCG Digital Ventures

  • Defined the technical direction for the internal tools team, striking a balance between business needs and long-term maintenance
  • Migrated a legacy system onto a modern frontend stack (React and TypeScript), boosting development speed and quality
  • Brought consistency to the design system, and improved accessibility
November 2017 – June 2019

Software Engineer, Movinga

  • Brought consistency to the company’s infrastructure using Terraform and Ansible, reducing infrastructure operating costs by 40–50%
  • Introduced monitoring and alerting using Prometheus and Grafana
  • Tightened security of applications, services, processes, and infrastructure
June 2013 – November 2017

Software Engineer, SoundCloud

  • Built infrastructure for the On SoundCloud partner program, including a flexible logic engine to handle frequently-changing business needs
  • Reduced the risk of outages, and ran workshops around incident response
  • Set up a central repository for organisation-wide technical documentation
  • Introduced design documents to the team, now adopted company-wide
  • Worked with the customer support team to improve their processes and tooling
September 2010 – May 2013

Software Engineer, MediaGeniX NG

Expanded the broadcasting solution for VIMN subsidiaries such as MTV, Comedy Central and Nickelodeon for divisions in Europe and Southeast Asia

2007 – 2009


At Cyan Worlds, modernized their main game site, bringing it to a #1 search result position, and set up translation workflows across seven languages

At Netlog, optimized an existing abuse-detection system for social networks

At dotProjects, developed a web-based machine translation system for large documents


2005 – 2010

Bachelor of Informatics, Master of Computer Science, Ghent University

Dissertation: Design of a recommendation system for offering services on social-network sites

Community involvement

Nanoc Creator and maintainer of Nanoc, a powerful static-site generator, used at GitHub, at GitLab, at PayPal, for Prometheus, at FOSDEM, for Atom, at Disney, and in many more places.

Open-source projects Creator and maintainer of several open-source projects, including cri, ddmemoize, and ddmetrics.

Mentoring I have mentored a diverse group of people, as part of CoderDojo, RailsGirls, and SoundCloud’s internship programs.

Public speaking I regularly give talks, of which Code as data (2018), How to memoize (2018), and Let’s write a parser! (2016) are my personal favorites.

Core skills

Natural languages

Dutch, English

Programming languages

JavaScript, TypeScript, HTML, CSS
Go, Java, Python
Rust, Clojure


Sinatra, React, Ruby on Rails
PostgreSQL, MySQL
Tableau, Node.js